Effect of pressure on individual hydrogen bonds in proteins, basic pancreatic trypsin inhibitor
Effect of pressure on individual hydrogen bonds in proteins, basic pancreatic trypsin inhibitor
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DOI：
10.1021/bi972288j
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发表时间：
1998-02-03
期刊：
影响因子：
2.9
通讯作者：
Akasaka, K
中科院分区：
文献类型：
--
作者：
Li, H;Yamada, H;Akasaka, K
通过在水溶液（90%（H_2O）-H ~（-1）/10%（H_2O）-H ~（-2））中，在750 MHz、1-2000 bar的不同静水压下进行二维H ~ 1 NMR测量，我们发现碱性胰蛋白酶抑制剂（BPTI）的肽NH质子在折叠状态下的信号随压力线性可逆地移动。这些质子的低场位移的强烈趋势表明，大多数的酰胺基团形成氢键与羰基或与水，这些氢弯曲缩短压力。NH质子与溶剂水的相互作用有利于表现出更大的压力诱导的位移比别人，显示的位移可以被用作诊断探针的NH基团与水的氢键状态。此外，我们还估计了单个H的缩短。距离的NH…O=C氢键在2000巴的基础上的经验位移距离相关的BPTI。估计缩短的距离在0-0.11埃的范围内从站点到站点变化很大，在转弯处较大，但在二级结构内部较小。这些变化表明BPTI内的体积波动是不均匀的，并且在高场的高压NMR可以为检测蛋白质中的微观结构波动提供独特的机会。
By performing two-dimensional H-1 NMR measurements at 750 MHz at varying hydrostatic pressure (1-2000 bar) in an aqueous environment (90% (H2O)-H-1/10% (H2O)-H-2), We found that the signals of the peptide NH protons of basic pancreatic trypsin inhibitor (BPTI) in the folded state shift their positions linearly and reversibly with pressure. The strong tendency for low-field shifts of these protons indicates that most of the amide groups form hydrogen bonds either with carbonyls or with water and that these hydrogen bends are shortened by pressure. The NH protons interacting favorably with solvent water tend to exhibit larger pressure-induced shifts than others, showing that the shift can be used as a diagnostic probe for the hydrogen bonding state of an NH group with water. Furthermore, we estimated shortening of individual H ... O distances of the NH ... O=C hydrogen bonds at 2000 bar on the basis of the empirical shift-distance correlation for BPTI. The estimated shortened distances varied considerably from site to site in the range of 0-0.11 Angstrom, larger in the turn but smaller in the interiors of secondary structures. These variations suggest that the volume fluctuation is heterogeneous within BPTI and that high-pressure NMR at high field can offer a unique opportunity for detecting microscopic structural fluctuation in proteins.